Bjorn’s pack launched from the fast-attack frigate Icebitten during the first few seconds of the assault. The boarding torpedo tore into the battlesphere alongside the others, wheeling and diving through exploding plasma bursts as the cogitators ran the trillions of calculations needed to deliver them to their target.

Locked down in his restraint harness, Bjorn saw the incoming ship-ident flash up on his helm display a split second before they hit it: Iota Malephelos. It didn’t mean anything to him then; it was just another one of the swarm of escort craft that the boarding parties were aiming to take down, freeing the capital ships to open up with their main gun-lines.

With a sickening crack, the torpedo crashed into the vessel’s hull, and Bjorn’s world dissolved into a juddering chaos of white noise and follow-up impacts. The torpedo’s prow smashed deep through layers of armoured decking, screeching like a banshee before grinding to a halt amid molten tangles of burning steel.

Meltas fired, clamps blew and the bow doors slammed open. The thunder of driver-engines, amplified by the close-pressed walls, gave way to the howl of escaping atmosphere. Bjorn ripped his restraints free, unhooked his bolter and charged out of the flaming aperture. His pack – Hvan, Ferith, Angvar, Eunwald, Urth and Godsmote – fell in close behind, their helm lenses shimmering crimson in the whirl of lambent shadows.

Bjorn no longer carried Blódbringer, the power axe he’d borne during the previous action, but now wielded a master-crafted lightning claw at the end of his left arm and bolter in his right gauntlet. The fighting was heavy, first against well-armed ship menials, then against the real targets: Alpha Legionnaires. The traitors emerged from the flickering shadows, their scale-pattern armour dark under failing lumen-strips. The pack wiped out the three of them, overwhelming in both numbers and speed. They stayed tight after that, sweeping down narrow feeder-corridors with the blood still hot on their blades.

More mortals were slain as the pack zeroed in on the objective, all members acting in concert, driven to a greater pitch of savagery by the burning need for vengeance.

The sternest test came just before the command bridge – an Alpha Legion champion in Terminator plate, backed up by a dozen more Space Marines and mortal auxiliaries, blocking further access amid the criss-cross ironwork of barricades. The legionnaire came straight towards them, chainblades revving under blazing combi-bolters. Hvan was blasted out of contention and thrown against the deck in a hail of shells. Godsmote ducked down below the volleys; his chainsword lashed out to bite, but was kicked away and crunched into a bulkhead. Urth and Eunwald slammed themselves back against the corridor’s walls, launching ranged fire at the enemy.